The fast ninety, you set up for where he is going to be, then fire when he crosses the wire. With a slow merchant, you would usually fire at about 10-12° before as he crosses the wire, a fast merchant would be about 15° before, and in this case, with an even faster warship, and you were probably further back, the 20° before worked. So you set-up for zero°, looked at 340°, and as he came across the wire, you shot, the torps went up the 0°, and intercepted there... correct?
